(BFM Stock Exchange) – The action of biotech founded by Daniel Cohen collapses Friday morning, while Pharnext will have to get back to work. If the leader hoped to obtain the marketing authorization of PXT3003 for the treatment of an orphan disease called Charcot-Marie-Tooth by the beginning of 2020, the US drug authority said it would be better to repeat a trial. confirmatory.
Camoufllet for the Pharnext issean biotech. Its stock price collapses 30.21% to 8.48 euros Friday in the first hour of quotations, the company has indicated that following discussions the Food and Drug Administration (FDA), the agency The American drug company recommended that a new phase 3 trial (the latest and most expensive trial before the application) be resumed for its experimental treatment of Charcot-Marie-Tooth Disease (CMT), the most common Hereditary neurological diseases with 125,000 patients in Europe and the United States.
Pharnext had devised a new combination of three known molecules (baclofen, naltrexone and sorbitol) at very low doses but acting synergistically to treat this chronic disease without approved treatment. In the case of molecules already approved for more than 30 years and at much lower doses than in their original indication, the company was exempted from starting with phase 1 (where only safety is verified) to begin clinical development. directly in phase 2 (where the first efficacy data are collected). This had been performed on 80 patients during the 2011-2012 period, and had shown a significant improvement in the patient's condition, measured by an improvement in the score on the ONLS (Overall Neuropathy Limitation Scale) scale. to assess the degree of disability.
At the end of 2015, the company was able to start a phase 3 trial (a pivotal study aimed at confirming the results of a larger population), aiming to test two different dosages of the treatment as well as a placebo (ie three cohorts) out of 300 patients. total. Introduced on the stock market in 2016, Pharnext finally convinced 323 patients with CMT type 1A to take part in the trial, called PLEO-CMT, and conducted in some 30 hospitals in both Europe and the United States. United States and Canada. In accordance with the timetable communicated to the introduction, the results were presented in the second half of 2018.
On average, high-dose patients experienced an average 0.4 point reduction in the ONLS score (12 gradations), close to the average improvement seen in phase 2 and above the level considered significant. (0.3 point) by the agencies. However, Pharnext had recognized that only 55 patients were able to receive the high dose, compared with 93 the low dose and 87 the placebo, because of "unexpected problems of stability in the pharmacological formulation of this assay.
However, because of this premature interruption of the maximum dose cohort, the FDA recommended that Pharnext conduct an additional phase 3 clinical study for the purpose of the registration dossier.
The company stresses, however, that by granting early 2019 the "fast track" designation to the product, the FDA recognizes the significant medical need that the disease presents, and encourages the company to exchange with it to finalize a clinical study plan.
The prospective calendar of filing of the registration dossier in the United States will be "subsequently adapted accordingly," says Pharnext, who hoped to obtain the sesame next year and market in stride.
"In view of the consistent efficacy results of PXT3003 observed in the various clinical studies already conducted and its very good safety profile to date, we remain deeply confident in the potential of PXT3003 as a therapeutic option, including patients with CMT1A need, "said in a statement Professor Daniel Cohen, founder and CEO of Pharnext. "We are definitely committed, as quickly as possible, to the development of a clinical study plan in agreement with the FDA, in order to make PXT3003 available to American patients".
It should be noted that at the same time, patients in Phase 3 who wished to continue treatment were able to take a nine-month open-label extension study (that is, all were able to switch to high dosing). The results of this extension study called PLEO-CMT-FU, designed to evaluate the long-term safety and tolerability of PXT3003, are to be revealed in the fourth quarter of 2019.
Guillaume Bayre – © 2019 BFM Stock Exchange